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path: root/drivers/pci/pcie_imx.c
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Diffstat (limited to 'drivers/pci/pcie_imx.c')
-rw-r--r--drivers/pci/pcie_imx.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c
index 732d59d..eab0a2b 100644
--- a/drivers/pci/pcie_imx.c
+++ b/drivers/pci/pcie_imx.c
@@ -42,6 +42,9 @@
/* PCIe Port Logic registers (memory-mapped) */
#define PL_OFFSET 0x700
+#define PCIE_PL_PFLR (PL_OFFSET + 0x08)
+#define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16)
+#define PCIE_PL_PFLR_FORCE_LINK (1 << 15)
#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
#define PCIE_PHY_DEBUG_R1_LINK_UP (1 << 4)
@@ -445,6 +448,36 @@ static int imx6_pcie_assert_core_reset(void)
/* Power up PCIe PHY */
setbits_le32(&gpc_regs->cntr, PCIE_PHY_PUP_REQ);
#else
+ /*
+ * If the bootloader already enabled the link we need some special
+ * handling to get the core back into a state where it is safe to
+ * touch it for configuration. As there is no dedicated reset signal
+ * wired up for MX6QDL, we need to manually force LTSSM into "detect"
+ * state before completely disabling LTSSM, which is a prerequisite
+ * for core configuration.
+ *
+ * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
+ * indication that the bootloader activated the link.
+ */
+ if (is_mx6dq()) {
+ u32 val, gpr1, gpr12;
+
+ gpr1 = readl(&iomuxc_regs->gpr[1]);
+ gpr12 = readl(&iomuxc_regs->gpr[12]);
+ if ((gpr1 & IOMUXC_GPR1_PCIE_REF_CLK_EN) &&
+ (gpr12 & IOMUXC_GPR12_PCIE_CTL_2)) {
+ val = readl(MX6_DBI_ADDR + PCIE_PL_PFLR);
+ val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
+ val |= PCIE_PL_PFLR_FORCE_LINK;
+
+ imx_pcie_fix_dabt_handler(true);
+ writel(val, MX6_DBI_ADDR + PCIE_PL_PFLR);
+ imx_pcie_fix_dabt_handler(false);
+
+ gpr12 &= ~IOMUXC_GPR12_PCIE_CTL_2;
+ writel(val, &iomuxc_regs->gpr[12]);
+ }
+ }
setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
#endif
@@ -652,6 +685,11 @@ void imx_pcie_init(void)
}
}
+void imx_pcie_remove(void)
+{
+ imx6_pcie_assert_core_reset();
+}
+
/* Probe function. */
void pci_init_board(void)
{